Low-Temperature Specific Heat and Electrical Resistivity Measurements of Hydrogen-Absorbed Pd–Zr and Ni–Zr Metallic Glasses

Abstract

The low-temperature specific heats (1.5–6 K) and the electrical resistivities (2–300 K) have been measured on liquid quenched Pd_0.33Zr_0.67H_x,Pd_0.35Zr_0.65H_x and Ni_0.35Zr_0.65H_x (0≤x≤1.2) ternary metallic glasses. Low-temperature specific heat data showed a substantial reduction in both the superconducting transition temperature and the density of states at the Fermi level but an increase in the Debye temperature upon hydrogenation. The results can be interpreted on the basis of the fact that hydrogen atoms tend to be trapped in tetrahedral sites surrounded by Zr-atoms. The electrical resistivities in the range 30–300 K can be well fitted to an empirical equation ρ⁄ρ₀=A+B exp (−T⁄Δ) for all alloys studied. Attention is focused on the Mooij correlation in the resistivity range 200–300 μΩ·cm and also on the presence of a correlation between the characteristic temperature Δ and the Debye temperature Θ_D.